Motors and engines often use a cylindrical chamber that houses a piston that moves up and down in the chamber. At the top of the chamber, an air/fuel mixture is compressed and if ignited, generates pressure that drives the piston back down the chamber. The lower part of the piston is connected to an offset driveshaft which pushes the piston back up again as the piston goes through its full cycle of motion.
While these approaches have been used with much success, there are challenges to efficiency. For instance, moving the piston toward top dead center during compression, reversing the piston's direction by accelerating the piston in an opposite direction upon ignition, then reversing the piston again for compression can be a relatively inefficient manner in which to generate power. Further, with various cycles implemented for intake and exhaust, inefficiencies can grow. These approaches are also subject to friction and heat loss. These and other matters have presented challenges to the efficient use of motors and engines for a variety of applications.